EP0003848A1 - Digitales Nachrichtenübertragungssystem - Google Patents

Digitales Nachrichtenübertragungssystem Download PDF

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Publication number
EP0003848A1
EP0003848A1 EP79100558A EP79100558A EP0003848A1 EP 0003848 A1 EP0003848 A1 EP 0003848A1 EP 79100558 A EP79100558 A EP 79100558A EP 79100558 A EP79100558 A EP 79100558A EP 0003848 A1 EP0003848 A1 EP 0003848A1
Authority
EP
European Patent Office
Prior art keywords
output
input
frequency
switch
receiving part
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP79100558A
Other languages
German (de)
English (en)
French (fr)
Inventor
Herbert Dipl.-Ing. Strehl
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original Assignee
Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens AG filed Critical Siemens AG
Publication of EP0003848A1 publication Critical patent/EP0003848A1/de
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/14—Two-way operation using the same type of signal, i.e. duplex
    • H04L5/143—Two-way operation using the same type of signal, i.e. duplex for modulated signals

Definitions

  • the invention relates to a digital message transmission system with two end points connected by a two-wire line, which contain an hybrid circuit, a transmitting part, a receiving part and a paging device.
  • fork circuits bridge circuits
  • fork circuits are used to separate the forward and backward direction on two-wire lines, because the moderate blocking attenuation, which is dependent on the respective line impedance, only causes listening to one's own speech.
  • the moderate blocking attenuation of the hybrid circuit can cause a disturbance of the reception signal by the own transmission signal. This is the case both with voice signal codes and with data devices.
  • This difficulty can be countered either by improving fork lock damping or by using separate position methods.
  • the former is effected according to DE-AS 2 628 852 by automatic adjustment of the replica or according to DE-OS 2 543 130 by compensating for the own transmission pulses in the receiving branch.
  • the latter can be implemented either according to DE-PS 2 040 401 with time division multiplex technology or with frequency division multiplex technology.
  • the methods for improving the fork lock damping have the disadvantage that a range of significantly greater than 4 km cannot be achieved because then even with improved fork damping, the interference of the weak received signals by the own transmission signals becomes too great. In addition, a reserve for the near-end crosstalk must still be available when used in the local network.
  • a transmission bit rate of, for example, 256 kbit / s runs the risk of conflicting with the interference radiation protection conditions if the transmission system is used on unshielded lines.
  • the object of the invention is to implement such a system with high barrier damping with relatively little effort, which also eliminates near-end crosstalk.
  • this object is achieved according to the invention in that a transmitting part which transmits signals in a first frequency position and a receiving part which receives signals in a second frequency position are provided in the calling terminal and in that called end station a transmitting part that sends signals in the second frequency position, and a receiving part are provided that receives signals in the first frequency position.
  • the blocking attenuation can be increased to the values required for a greater range without the effort for the circuit exceeding the extent that the subscriber can accept.
  • an analog-to-digital converter the input of which serves as the input of the transmitting part, a toggle switch, the input of which is connected to the output of the analog-to-digital converter, and a first frequency converter are provided in the transmitting part whose input is connected to a first output of the transmission switch, whose output is connected to a second output of the transmission switch and whose output serves as the output of the transmission part, and if in the receiving part a low-pass and a high-pass filter, the inputs of which serve as the input of the receiving part, a second frequency converter, whose input is connected to the output of the high pass, a reception switch, whose one input is connected to the output of the second frequency converter and the other input of which are connected to the output of the low-pass filter, and a digital-to-analog converter are provided, the input of which is connected to the output of the receiving switch and the output of which serves as the output of the receiving part.
  • an automatic changeover device ensures that, for example, the calling subscriber always transmits in the lower frequency range and the called subscriber always answers in the upper frequency range.
  • This switching device can be triggered, for example, by the call signal.
  • This method is advantageous when an existing two-wire private branch exchange is to be converted to digital operation, because hardly any changes are then necessary in the two-wire exchange.
  • central converters By differentiating outgoing and incoming traffic, central converters can be introduced in an advantageous manner.
  • the terminal I contains a transmitting part 1 and a receiving part 2.
  • the transmitting part 1 contains an analog-to-digital converter 5, a transmission switch 6 and a frequency converter 7.
  • the receiving part 2 contains one Low-pass filter 11, a high-pass filter 12, a frequency converter 13, a reception switch 14 and a digital-to-analog converter 15. Furthermore, a switch control 21, a receiver 26, a microphone 27 and a hybrid circuit 23 are provided. Instead of the low pass 11 and the high pass 12, a crossover can also be used.
  • the transmitting part 3 is constructed like the transmitting part 1 and the receiving part 4 as the receiving part 2.
  • a switch controller 22, a receiver 28, 'a microphone 29 and a hybrid circuit 24 are also provided. The transmission takes place via a two-wire line 25.
  • switch controls 21 and 22 switch transmission switches 6 and 9 and reception switches 14 and 19 in the manner shown.
  • the analog-to-digital converter 5 converts the analog signal into a digital signal, the power spectrum of which focuses on the frequency f u .
  • This digital signal passes through the changeover switch 6, the hybrid circuit 23, the two-wire line 25, the hybrid circuit 24, the low pass 16 and the receive changeover switch 19 to the digital-to-analog converter 20, which converts the digital signal into an analog signal that can be heard on the receiver 28 .
  • this analog signal is converted into a digital signal in the analog-digital converter 8, which also has the focus of its power spectrum at the frequency f u .
  • This signal runs via the transmission switch 9 to the frequency converter 10, which converts the digital signal into a digital signal with a focus on the power spectrum at the frequency f.
  • This Signal runs through the hybrid circuit 24, the two-wire line 25, the hybrid circuit 23, the high-pass filter 12 to the frequency converter 13, which converts the digital signal back into a spectrum with its focus on the frequency f. From there, the digital signal reaches the listener 26 via the reception switch 14 and the digital-to-analog converter 15. If the terminal II is the calling station, both the transmission switches 6 and 9 and both the reception switches 14 and 19 are switched and the method described plays itself into Opposite direction.
  • Fig. 2 shows in principle a separation of the center of gravity frequency from power spectra, as it is caused by transcoding the pulses a into the pulses b or c.
  • FIG. 3 shows a switching system with a two-wire switch 26 and four end stations 27 to 30.
  • the end stations 27 and 30 are calling end stations and the end stations 28 and 29 are called stations.
  • the transmission from the terminal 27 to the terminal 29 and from the terminal 30 to the terminal 28 takes place with a power spectrum with the maximum at the frequency f u .
  • the transmission in the opposite direction takes place in each case with signals of a power spectrum which has its maximum at the frequency f.
  • a disadvantage of this method is that the connecting line lengths of the two end points for the transmission add up and that, in unfavorable cases, near-end crosstalk disturbances are possible which can occur between the end points 27 and 28 or 29 and 30.
  • Fig. 4 shows a terminal I ', in which the transmission switch 6 and the reception switch 14 are fixed.
  • a transmission from the exchange to the terminal and in the lower frequency from the terminal to the exchange or vice versa is possible in the upper frequency range.
  • frequency converters are now required in the exchange. Instead of the fork 23 and the high pass 12, a crossover can also be used.
  • FIG. 5 shows such a system with a four-wire switch 31, with end stations 32 to 35 and frequency converters 36 to 39.
  • the frequency positions are interchanged with the frequency converters 36 to 39.
  • FIG. 6 shows a system with a two-wire exchange 40 and subscriber stations 41 to 44, in which the frequency converters 45 and 46 are arranged centrally and a distinction is made between incoming and outgoing traffic.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
  • Transceivers (AREA)
  • Bidirectional Digital Transmission (AREA)
  • Transmission Systems Not Characterized By The Medium Used For Transmission (AREA)
  • Use Of Switch Circuits For Exchanges And Methods Of Control Of Multiplex Exchanges (AREA)
  • Nitrogen And Oxygen Or Sulfur-Condensed Heterocyclic Ring Systems (AREA)
EP79100558A 1978-02-23 1979-02-23 Digitales Nachrichtenübertragungssystem Ceased EP0003848A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19782807785 DE2807785A1 (de) 1978-02-23 1978-02-23 Digitales nachrichtenuebertragungssystem
DE2807785 1978-02-23

Publications (1)

Publication Number Publication Date
EP0003848A1 true EP0003848A1 (de) 1979-09-05

Family

ID=6032753

Family Applications (1)

Application Number Title Priority Date Filing Date
EP79100558A Ceased EP0003848A1 (de) 1978-02-23 1979-02-23 Digitales Nachrichtenübertragungssystem

Country Status (13)

Country Link
US (1) US4236244A (pt)
EP (1) EP0003848A1 (pt)
JP (1) JPS5513595A (pt)
AR (1) AR218363A1 (pt)
AU (1) AU517838B2 (pt)
BE (1) BE873804A (pt)
BR (1) BR7901158A (pt)
DE (1) DE2807785A1 (pt)
DK (1) DK77379A (pt)
FI (1) FI790603A (pt)
GB (1) GB2016871B (pt)
NO (1) NO790596L (pt)
ZA (1) ZA79892B (pt)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2916576C3 (de) * 1979-04-24 1981-12-10 Siemens AG, 1000 Berlin und 8000 München Digital-Fernmeldesystem für Zweidraht-Getrenntlage-Betrieb
CA1159972A (en) * 1980-05-15 1984-01-03 Zdzistaw A. A. Krajewski 2-wire frequency division multiplex system
DE3019835C2 (de) * 1980-05-23 1983-12-01 Siemens AG, 1000 Berlin und 8000 München Übertragerfreie Gabelschaltung
JPS5860577A (ja) * 1981-10-07 1983-04-11 Hitachi Ltd 半導体装置
GB2146509B (en) * 1983-09-10 1986-08-13 Stc Plc Data transmission system
DE3702202A1 (de) * 1987-01-26 1988-08-04 Dirr Josef Verfahren fuer die uebertragung analoger und/oder digitaler information, insbesondere unter zwischenschaltung einer, 2er oder mehrerer vermittlungen in fernmeldeanlagen
DE19844457C1 (de) * 1998-09-28 2000-07-06 Siemens Ag Verfahren zur Duplex-Datenübertragung mit QAM und Demodulator zur Verwendung in diesem Verfahren
CN103226025B (zh) * 2012-12-17 2017-02-08 天津市北方阀门控制设备有限公司 一种两线制位置变送器电路
US11133864B1 (en) * 2020-04-24 2021-09-28 Ciena Corporation Measurement of crosstalk

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3655915A (en) * 1970-05-07 1972-04-11 Gen Datacomm Ind Inc Closed loop test method and apparatus for duplex data transmission modem
US3715496A (en) * 1971-10-21 1973-02-06 Ibm Digital band-pass filter for a single circuit full duplex transmission system
DE2141198A1 (de) * 1971-08-17 1973-03-01 Siemens Ag Verfahren zur schleifenmessung bei modem fuer zweidrahtbetrieb
US3846582A (en) * 1973-08-06 1974-11-05 Bell Telephone Labor Inc Data transmission terminal for fsk frequency duplexed systems
US3937882A (en) * 1974-04-11 1976-02-10 Vadic Corporation Full-duplex communication system on a two wire line

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3993867A (en) * 1974-10-15 1976-11-23 Motorola, Inc. Digital single signal line full duplex method and apparatus
US3936602A (en) * 1974-10-23 1976-02-03 Northern Electric Company Limited Full duplex data transmission system using two speeds of diphase signal for simplified sync
DE2543696C3 (de) * 1975-09-30 1980-04-17 Siemens Ag, 1000 Berlin Und 8000 Muenchen Schaltungsanordnung zur Umsetzung von Digital-Signalen in Analog-Signale und zur Umsetzung von Analog-Signalen in Digital-Signale
US4041398A (en) * 1976-06-03 1977-08-09 Icc, Inc. Bi-directional digital communication network

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3655915A (en) * 1970-05-07 1972-04-11 Gen Datacomm Ind Inc Closed loop test method and apparatus for duplex data transmission modem
DE2141198A1 (de) * 1971-08-17 1973-03-01 Siemens Ag Verfahren zur schleifenmessung bei modem fuer zweidrahtbetrieb
US3715496A (en) * 1971-10-21 1973-02-06 Ibm Digital band-pass filter for a single circuit full duplex transmission system
US3846582A (en) * 1973-08-06 1974-11-05 Bell Telephone Labor Inc Data transmission terminal for fsk frequency duplexed systems
US3937882A (en) * 1974-04-11 1976-02-10 Vadic Corporation Full-duplex communication system on a two wire line

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
NACHRICHTENTECHNISCHE ZEITSCHRIFT, Vol. 29, Nr. 6, Juni 1976, Berlin, T. IRMER: 'Digitale Uebertragungstechnik für das Datenfernnetz in der Bundesrepublik Deutschland', Seiten 432 - 435 *
ONDE ELECTRIQUE, Vol. 45, Nr. 458, Mai 1965, Paris, M. MANIERE: 'La transmission de données, méthodes de modulation', Seiten 583 - 588 *

Also Published As

Publication number Publication date
NO790596L (no) 1979-08-24
DK77379A (da) 1979-08-24
JPS5513595A (en) 1980-01-30
FI790603A (fi) 1979-08-24
AU517838B2 (en) 1981-08-27
GB2016871A (en) 1979-09-26
BR7901158A (pt) 1979-10-09
GB2016871B (en) 1982-04-15
BE873804A (fr) 1979-05-16
US4236244A (en) 1980-11-25
AR218363A1 (es) 1980-05-30
AU4451379A (en) 1979-08-30
ZA79892B (en) 1980-03-26
DE2807785A1 (de) 1979-08-30

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Inventor name: STREHL, HERBERT, DIPL.-ING.